Phonic Ear Radium 920SR User Manual page 38

put on microphone and adjust for proper distance
15
from mouth
Maximum distance from mic to mouth is 6 in/(15cm); 3 in/(7.5cm) is ideal.
optimum
AT0655 boom mic
performance:
7.5cm/3in
AT0816 collar mic
performance:
optional
(two wearing options)
AT0814 earhook mic
performance:
15cm/
6in max.
AT0291-L directional lapel mic
performance:
36